It is the purpose of this project to study the immune mechanisms involved in sporozoite-induced infections in simian (Plasmodium knowlesi) malaria. Studies underway are concerned with: 1) characterization of sporozoite surface antigens; 2) development of methods for immunization of monkeys with P. knowlesi sporozoites. BIBLIOGRAPHIC REFERENCE: Chen, D.H., Tigelaar, R.E., and Weinbaum, F.I.: Immunity to sporozoite-induced malaria infection in mice I. The effect of immunization of T and B cell-deficient mice. J. Immunol. 118: 1322-1327, 1977.